Hydro excavation heating system and related methods

ABSTRACT

A hydro excavation heating system includes an internal combustion engine having an exhaust gas stream, a heat exchanger coupled to the exhaust gas stream and configured to heat hydro excavation water by transferring heat from the exhaust gas stream to the hydro excavation water circulating therethrough, and a tank for storing the hydro excavation water. The system also includes a water pump having an inlet coupled to an outlet of the tank storing the hydro excavation water, a hydro excavation hose coupled to an outlet of the water pump, and a coupling coupled to the hydro excavation hose and to an inlet of the heat exchanger to define a closed circulation path through the system when heating the hydro excavation water, where the coupling is configured to disconnect from the heat exchanger in order to use the hydro excavation water during a hydro excavation operation.

FIELD

The present invention relates to the field of heating systems, and, more particularly, to a hydro excavation heating system and related methods.

BACKGROUND

In northern climates, frozen ground is a problem for the construction industry during the winter months. Cold winter temperatures can cause water and sewer pipes to freeze. Frozen ground also interferes with any earth moving operation such as trenching, excavating for foundation footings, leveling for a concrete slab, or digging a gravesite. Consequently, in northern climates, mobile ground heating or thawing systems are known.

One common type of mobile heating system known in the prior art comprises a kerosene burner and a fan for discharging large volumes of heated air into a temporary enclosure which confines the heated air above the area which is to be thawed. Such systems are also used to blow heated air into an unfinished structure during later phases of construction. However, when such systems are used in this latter application, they are found to have a significant problem with water vapor, carbon dioxide, and other combustion products, which build up inside the unfinished structure. It is not desirable to expose workmen for many hours to the combustion products which emanate from such devices. Further, since water vapor is one of the principal byproducts of combustion, condensation of the water vapor in the structure can be a problem in cold weather. Such systems are also known to have a low thermal efficiency and are expensive to run because of high fuel consumption.

In another type of mobile ground heating or thawing system, a boiler, a pump and a ground heat exchanger in the form of a hose, including a plurality of ground-engaging probes, are all filled with a heat transfer fluid. The heat transfer fluid is pumped from the boiler through the hose the probes for the purpose of transferring heat to the ground or to a structure. Systems which use such a fluid coupling between the ground and a boiler are known to have better heat transfer efficiency than those employing a burner and a fan. Such systems also provide the advantage of being able to more precisely apply heat to a desired area. In such systems, heat is applied to the ground with fluid-filled rods, which are inserted into holes which are drilled into the frozen ground, or with fluid-filled hoses which are laid over the ground and covered with a suitable quantity of sand and/or other insulating materials.

SUMMARY

In view of the foregoing background, it is therefore an object of the present invention to provide.

This and other objects, features, and advantages in accordance with the present invention are provided by a hydro excavation heating system that includes an internal combustion engine having an exhaust gas stream, a heat exchanger coupled to the exhaust gas stream and configured to heat hydro excavation water by transferring heat from the exhaust gas stream to the hydro excavation water circulating therethrough, and a tank for storing the hydro excavation water. The system also includes a water pump having an inlet coupled to an outlet of the tank storing the hydro excavation water, a hydro excavation hose coupled to an outlet of the water pump, and a coupling coupled to the hydro excavation hose and to an inlet of the heat exchanger to define a closed circulation path through the system when heating the hydro excavation water, where the coupling is configured to disconnect from the heat exchanger in order to use the hydro excavation water during a hydro excavation operation.

In another embodiment a method of heating hydro excavation water is disclosed. The method includes heating hydro excavation water by transferring heat from an exhaust gas stream of an internal combustion engine to the hydro excavation water using a heat exchanger, pumping the hydro excavation water from the heat exchanger to a tank, and pumping the hydro excavation water from the tank through a hydro excavation hose. The method also includes returning the hydro excavation water to the heat exchanger and continuing to recirculate the hydro excavation water through the heat exchanger until a temperature of the hydro excavation water exceeds a threshold temperature.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is block diagram of a hydro excavation heating system in accordance with the invention;

FIG. 2 is a block diagram of a heat exchanger shown in FIG. 1;

FIG. 3 is a cross sectional view of the heat exchanger of FIG. 1 showing the exhaust and water flow through the heat exchanger in a particular embodiment of the invention;

FIG. 4 is a cross sectional view taken in the direction of line 4-4 of FIG. 3;

FIG. 4a is a top plan view of a baffle of the heat exchanger; and

FIG. 5 is a perspective view of the hydro excavation heating system mounted to a trailer.

DETAILED DESCRIPTION

The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout, and prime notation is used to indicate similar elements in alternative embodiments.

Referring initially to FIG. 1, a hydro excavation heating system 100 is shown. An internal combustion engine 102 is used as a heat source by transferring heat in the exhaust gases from the engine 102 before being expelled to the atmosphere via exhaust piping 104.

A heat exchanger 106 is secured to the exhaust piping 104 and serves as a mechanism to transfer the heat in the exhaust gases to the hydro excavation water. A recirculating pump 108 is coupled in fluid communication with the heat exchanger 106 via hot line piping 110. The hot line piping 110 conveys the heated hydro excavation water from the heat exchanger 106 to the water tanks 112 a and 112 b. The recirculating pump 108 is configured to pump the hydro excavation water continuously from the heat exchanger 106 to the tanks 112 a, 112 b and hydro excavation hose 120, and back to the heat exchanger 106. The hydro excavation hose 120 is shown schematically being stored on a hose reel in FIG. 1.

The water tanks 112 a, 112 b are in fluid communication with a secondary temperature sensor 116 via tank outlet piping 114. Downstream of the secondary temperature sensor 116 is a hydro excavation pump 118, which is coupled to a first end of the hydro excavation hose 120. A second end of the hydro excavation hose is coupled to a quick connect coupling 122. The quick connect coupling 122 is configured so that the second end of the hydro excavation hose 120 can be disconnected from recirculating the hydro excavation water back to the heat exchanger 106 and the hydro excavation water can be used for hydro excavation. When the second end of the hydro excavation hose 120 is connected with the quick connect coupling 122, the hydro excavation water is circulated back to the heat exchanger 106.

The quick connect coupling 122 is coupled to a primary temperature sensor 132 and downstream of the primary temperature sensor 132 is a control valve 124. The control valve 124 is configured to control the flow of the hydro excavation water through the heat exchanger 124. When the control valve 124 is in a first position, the hydro excavation water is directed to the heat exchanger 106. In a second position, the control valve 124 directs the hydro excavation water to bypass the heat exchanger 124.

The hydro excavation heating system 100 includes a controller 130 having a processor coupled to a memory. The controller 130 is coupled to the primary and secondary temperature sensors 122, 132 and the control valve 124. The controller 130 is configured to operate the control valve 124 in order to control the rate of flow of the hydro excavation water to the heat exchanger 106 by comparing the first temperature from the primary temperature sensor 132 to the second temperature from the secondary temperature sensor 116 and changing the rate of flow in response thereto. For example, once the temperature of hydra excavation water is at the desired temperature or exceeds a threshold temperature, the controller 130 signals the control valve 124 to move to the bypass position in order to direct the hydro excavation water to divert to the bypass piping 126 around the heat exchanger 106. A one-way valve 128 is in fluid communication between the bypass piping 126 and the hot line piping 110.

Referring now to FIG. 2, the heat exchanger 106 includes a chamber 202 that has in inlet for the exhaust gas from the internal combustion engine 102, and an outlet coupled to the exhaust piping 104. In addition, the chamber 202 includes an inlet for the hydro excavation water being recirculated from the tanks 112 a, 112 b to be heated. The control valve 124 is used to control the flow of the hydro excavation water through the chamber 202 and the flow to bypass the chamber 202.

FIG. 3 is a cross sectional view of the heat exchanger 106 showing the exhaust and water flow through the chamber 202 of the heat exchanger 106. A tube 204 may be concentrically installed within the chamber 102 and configured for coil piping 206 to be wrapped around an outer surface of the tube 204. The coil piping 206 is in fluid communication with the inlet of the chamber and the control valve 124. As the hydro excavation water flows through the coil piping 206, heat from the exhaust gas is transferred to the hydro excavation water in the coil piping 206. The configuration of the coil piping 206 is such that the hydro excavation water takes longer to flow through the chamber 202 than if the coil piping was linear from inlet to the outlet of the chamber 202. This increases the heat transfer rate. Also to improve the efficiency of the heat transfer, the tube 202 includes a series of baffles 208. This slows the flow of the exhaust gas through the chamber 202 and provide an increase in the contact time between the hydro excavation water flowing in the coil piping 206 and the exhaust gas from the internal combustion engine 102.

As shown in FIG. 4, which is a cross sectional view taken in the direction of line 4-4 of FIG. 3, the coil piping 206 spirals around between an outer surface of the tube 204 and an inner surface of the chamber 202. The baffles 208 inside the tube 204 include a series of holes 210 that slows the flow of the exhaust gas through the tube 204 while a portion of the exhaust has flow around the outer surface of the tube 204 where the coil piping 206 is located in this particular embodiment.

FIG. 4a is a top plan view of the baffle 208. The tube 204 may have a different configuration of baffles than that shown such as alternating half-walls dispersed along the length of the tube, for example. The baffles 208 are configured to increase the heat exchange between the exhaust gas and the coil piping 206 where the coil piping may comprise copper or another heat conducting material.

FIG. 5 is a perspective view of the hydro excavation heating system 100 mounted to a trailer 214. A debris tank 212 is also mounted to the trailer 214 along with the hydro excavation hose 120 on a hose reel. The internal combustion engine 102 is shown mounted towards a front portion of the trailer and the tanks 112 a, 112 b towards a rear portion of the trailer 214. The exhaust piping 104 is shown discharging upward and away from the equipment mounted to the trailer 214. The controller 130 may be mounted proximate the internal combustion engine 102 and where it is easily accessible.

Many modifications and other embodiments of the invention will come to the mind of one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings.

Therefore, it is understood that the invention is not to be limited to the specific embodiments disclosed, and that modifications and embodiments are intended to be included within the scope of the appended claims. 

That which is claimed is:
 1. A hydro excavation heating system comprising: an internal combustion engine having an exhaust gas stream; a heat exchanger coupled to the exhaust gas stream and configured to heat hydro excavation water by transferring heat from the exhaust gas stream to the hydro excavation water circulating therethrough; a tank for storing the hydro excavation water and having an inlet coupled to an outlet of the heat exchanger and configured to receive hydro excavation water heated by the heat exchanger; a water pump having an inlet coupled to an outlet of the tank storing the hydro excavation water; a hydro excavation hose having a first end and a second end, the first end coupled to an outlet of the water pump; and a coupling coupled to a second end of the hydro excavation hose and to an inlet of the heat exchanger to define a closed circulation path through the system when heating the hydro excavation water, wherein the coupling is configured to disconnect from the heat exchanger in order to use the hydro excavation water during a hydro excavation operation.
 2. The hydro excavation heating system of claim 1, further comprising a hose reel for winding the hydro excavation hose thereon.
 3. The hydro excavation heating system of claim 1, further comprising a first temperature sensor interposed between the hydro excavation hose and the heat exchanger and configured to provide a first temperature of the hydra excavation water at a first location.
 4. The hydro excavation heating system of claim 3, further comprising a control valve coupled between the heat exchanger and the hydro excavation hose and configured to control a rate of flow of the hydro excavation water to the heat exchanger.
 5. The hydro excavation heating system of claim 4, further comprising a second temperature sensor interposed between the tank and the water pump and configured to provide a second temperature of the hydro excavation water at a second location.
 6. The hydro excavation heating system of claim 5, further comprising a controller coupled to the first and second temperature sensors and the control valve, the controller configured to operate the control valve in order to control the rate of flow of the hydro excavation water to the heat exchanger by comparing the first temperature to the second temperature and changing the rate of flow in response thereto.
 7. The hydro excavation heating system of claim 1, further comprising a recirculation line in fluid communication between the tank and the hose reel and configured to recirculate the hydro excavation water through the length of hydro excavation hose on the hose reel and back to the tank when the second temperature exceeds a threshold temperature.
 8. The hydro excavation heating equipment of claim 1, further comprising a vehicle having the internal combustion engine therein.
 9. The hydro excavation equipment of claim 1, wherein the water pump is driven by the internal combustion engine.
 10. A hydro excavation heating system comprising: an internal combustion engine having an exhaust gas stream; a heat exchanger coupled to the exhaust gas stream and configured to heat hydro excavation water by transferring heat from the exhaust gas stream to the hydro excavation water circulating therethrough; a tank for storing the hydro excavation water and having an inlet coupled to an outlet of the heat exchanger and configured to receive hydro excavation water heated by the heat exchanger; a water pump having an inlet coupled to an outlet of the tank storing the hydro excavation water; a hydro excavation hose having a first end and a second end, the first end coupled to an outlet of the water pump; a coupling coupled to a second end of the hydro excavation hose and to an inlet of the heat exchanger to define a closed circulation path through the system when heating the hydro excavation water, wherein the coupling is configured to disconnect from the heat exchanger in order to use the hydro excavation water during a hydro excavation operation; a first temperature sensor interposed between the hydro excavation hose and the heat exchanger and configured to provide a first temperature of the hydro excavation water at a first location; and a control valve coupled between the heat exchanger and the hydro excavation hose and configured to control a rate of flow of the hydro excavation water to the heat exchanger.
 11. The hydro excavation heating system of claim 10, further comprising a second temperature sensor interposed between the tank and the water pump and configured to provide a second temperature of the hydro excavation water at a second location.
 12. The hydro excavation heating system of claim 11, further comprising a controller coupled to the first and second temperature sensors and the control valve, the controller configured to operate the control valve in order to control the rate of flow of the hydro excavation water to the heat exchanger by comparing the first temperature to the second temperature and changing the rate of flow in response thereto.
 13. The hydro excavation heating system of claim 10, further comprising a recirculation line in fluid communication between the tank and the hydro excavation hose and configured to recirculate the hydro excavation water through the hydro excavation hose and back to the tank when the second temperature exceeds a threshold temperature.
 14. The hydro excavation heating equipment of claim 10, further comprising a vehicle having the internal combustion engine therein.
 15. The hydro excavation equipment of claim 10, wherein the water pump is driven by the internal combustion engine.
 16. A method of heating hydro excavation water comprising: heating hydro excavation water by transferring heat from an exhaust gas stream of an internal combustion engine to the hydro excavation water using a heat exchanger; pumping the hydro excavation water from the heat exchanger to a tank; pumping the hydro excavation water from the tank through a hydro excavation hose; and returning the hydro excavation water to the heat exchanger and continuing to recirculate the hydro excavation water through the heat exchanger until a temperature of the hydro excavation water exceeds a threshold temperature.
 17. The method of claim 16, further comprising controlling a rate of flow of the hydro excavation water using a control valve coupled to the heat exchanger.
 18. The method of claim 16, wherein the exhaust gas stream is provided by the internal combustion engine of a vehicle.
 19. The method of claim 16, wherein the internal combustion engine is pumping the hydro excavation water from the heat exchanger to the tank and from the tank through the excavation hose.
 20. The method of claim 16, further comprising recirculating the hydro excavation water only through the tank and the hydro excavation hose when the threshold temperature is exceeded. 